Effects of Silage pH on Voluntary Intake of Corn Silage and Alfalfa Haylage

Abstract

Effects of forage pH on voluntary intake of corn silage and alfalfa haylage were evaluated. Four (140 kg) Holstein steers were in a 4 × 4 Latin-square design with 15-day experimental periods in Trial 1. Treatments consisted of 1) fresh whole corn plant frozen at harvest, 2) fresh whole corn plant acidified with hydrochloric acid to the pH of corn silage, 3) corn silage, and 4) corn silage neutralized with sodium bicarbonate to the pH of fresh whole corn plant. Addition of acid to fresh whole corn plant reduced pH from 5.20 to 3.66 and organic matter intake .29 to 3.62 kg/day. Neutralization of corn silage acidity increased pH from 3.86 to 5.94 and organic matter intake .49 to 4.23 kg/day. In Trial 2, 16 Holstein heifers (290 kg) were fed one of the following treatments in an 8-wk experiment: 1) control corn silage, 2) corn silage plus added water, and 3) corn silage plus 7.0% sodium bicarbonate solution in amount identical to amount of water in 2. Water and sodium bicarbonate solution were added at 25 kg/100 kg of silage prior to feeding. Addition of water depressed intake of organic matter 1.16 kg to 6.64 kg/day. Addition of sodium bicarbonate increased silage pH to 7.11 versus 3.79 for control and increased organic matter intake .59 kg/day over animals fed water plus silage. In Trial 3, 16 Holstein heifers (250 kg) were fed in an 8-wk experiment haylage neutralized with 0, 1.f, 3.0, or 4.5.% sodium bicarbonate (dry matter). Silage pH increased from 4.48 in the controls to 5.78 at the highest addition of sodim bicarbonate. Sodium bicarbonate increased intake of organic matter in a linear response with the greatest increase (1.08 kg/day) at 4.5% sodium bicarbonate. Forage pH affects voluntary consumption of corn silage and alfalfa haylage, and neutralizing free acid with sodium bicarbonate increased intake. © 1985, American Dairy Science Association. All rights reserved.